Various operation for PCM data

mix.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

int mix(char *inbuf1, char *inbuf2, char *outbuf, int len, float vol1, float vol2)
{
	int16_t *inp1, *inp2;
	int16_t *outp;
	int cnt = len / sizeof(int16_t);
	
	inp1 = (int16_t*)inbuf1;
	inp2 = (int16_t*)inbuf2;
	outp = (int16_t*)outbuf;
	while (cnt-- > 0) {
		*outp++ = *inp1++ * vol1 + *inp2++ * vol2;
	}
	return (char*)outp - outbuf;
}

#define BUFSIZE 4096

int main(int argc, char** argv)
{
	FILE *fin1, *fin2;
	FILE *fout;
	char inbuf1[BUFSIZE], inbuf2[BUFSIZE], outbuf[BUFSIZE];
	int read_len1, read_len2, write_len;
	char *infile1 = argv[1];
	char *infile2 = argv[3];
	char *outfile = argv[5];
	float vol1, vol2;

	if (argc != 6) {
		fprintf(stderr, "usage: %s infile1 vol1 infile2 vol2 outfile\nSpecify vol1, vol2 in float\n", argv[0]);
		exit(1);
	}
	vol1 = strtof(argv[2], NULL);
	vol2 = strtof(argv[4], NULL);
	if ((fin1 = fopen(infile1, "r")) == NULL) {
		perror(infile1);
		exit(1);
	}
	if ((fin2 = fopen(infile2, "r")) == NULL) {
		perror(infile2);
		exit(1);
	}
	if ((fout = fopen(outfile, "w")) == NULL) {
		perror(outfile);
		exit(1);
	}
	while (!feof(fin1) && !feof(fin2)) {
		int read_len;
		read_len1 = fread(inbuf1, 1, sizeof inbuf1, fin1);
		read_len2 = fread(inbuf2, 1, sizeof inbuf2, fin2);
		read_len = (read_len1 > read_len2)? read_len2 : read_len1;
		write_len = mix(inbuf1, inbuf2, outbuf, read_len, vol1, vol2);
		printf("read_len1=%d read_len2=%d read_len=%d write_len=%d\n", read_len1, read_len2, read_len, write_len);
		fwrite(outbuf, 1, write_len, fout);
	}
	fclose(fin1);
	fclose(fin2);
	fclose(fout);
}

mono2left.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

int mono2left(char *inbuf, char *outbuf, int len)
{
	int16_t *inp;
	int16_t *outp;
	int cnt = len / sizeof(int16_t);
	
	inp = (int16_t*)inbuf;
	outp = (int16_t*)outbuf;
	while (cnt-- > 0) {
		*outp++ = *inp;
		*outp++ = 0;
		
		inp++;
	}
	return (char*)outp - outbuf;
}

#define BUFSIZE 4096

int main(int argc, char** argv)
{
	FILE *fin;
	FILE *fout;
	char inbuf[BUFSIZE], outbuf[BUFSIZE * 2];
	int read_len, write_len;
	char *infile = argv[1];
	char *outfile = argv[2];

	if (argc != 3) {
		fprintf(stderr, "usage: %s infile outfile\n", argv[0]);
		exit(1);
	}
	
	if ((fin = fopen(infile, "r")) == NULL) {
		perror(infile);
		exit(1);
	}
	if ((fout = fopen(outfile, "w")) == NULL) {
		perror(outfile);
		exit(1);
	}
	while (!feof(fin)) {
		read_len = fread(inbuf, 1, sizeof inbuf, fin);
		write_len = mono2left(inbuf, outbuf, read_len);
		fwrite(outbuf, 1, write_len, fout);
	}
	fclose(fin);
	fclose(fout);
}

mono2right.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

int mono2right(char *inbuf, char *outbuf, int len)
{
	int16_t *inp;
	int16_t *outp;
	int cnt = len / sizeof(int16_t);
	
	inp = (int16_t*)inbuf;
	outp = (int16_t*)outbuf;
	while (cnt-- > 0) {
		*outp++ = 0;
		*outp++ = *inp;
		
		inp++;
	}
	return (char*)outp - outbuf;
}

#define BUFSIZE 4096

int main(int argc, char** argv)
{
	FILE *fin;
	FILE *fout;
	char inbuf[BUFSIZE], outbuf[BUFSIZE * 2];
	int read_len, write_len;
	char *infile = argv[1];
	char *outfile = argv[2];

	if (argc != 3) {
		fprintf(stderr, "usage: %s infile outfile\n", argv[0]);
		exit(1);
	}
	
	if ((fin = fopen(infile, "r")) == NULL) {
		perror(infile);
		exit(1);
	}
	if ((fout = fopen(outfile, "w")) == NULL) {
		perror(outfile);
		exit(1);
	}
	while (!feof(fin)) {
		read_len = fread(inbuf, 1, sizeof inbuf, fin);
		write_len = mono2right(inbuf, outbuf, read_len);
		fwrite(outbuf, 1, write_len, fout);
	}
	fclose(fin);
	fclose(fout);
}

mono2stereo.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

int mono2stereo(char *inbuf, char *outbuf, int len)
{
	int16_t *inp;
	int16_t *outp;
	int cnt = len / sizeof(int16_t);
	
	inp = (int16_t*)inbuf;
	outp = (int16_t*)outbuf;
	while (cnt-- > 0) {
		*outp++ = *inp;
		*outp++ = *inp;
		
		inp++;
	}
	return (char*)outp - outbuf;
}

#define BUFSIZE 4096

int main(int argc, char** argv)
{
	FILE *fin;
	FILE *fout;
	char inbuf[BUFSIZE], outbuf[BUFSIZE * 2];
	int read_len, write_len;
	char *infile = argv[1];
	char *outfile = argv[2];

	if (argc != 3) {
		fprintf(stderr, "usage: %s infile outfile\n", argv[0]);
		exit(1);
	}
	
	if ((fin = fopen(infile, "r")) == NULL) {
		perror(infile);
		exit(1);
	}
	if ((fout = fopen(outfile, "w")) == NULL) {
		perror(outfile);
		exit(1);
	}
	while (!feof(fin)) {
		read_len = fread(inbuf, 1, sizeof inbuf, fin);
		write_len = mono2stereo(inbuf, outbuf, read_len);
		fwrite(outbuf, 1, write_len, fout);
	}
	fclose(fin);
	fclose(fout);
}

vol.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

int changeVol(char *inbuf, char *outbuf, int len, float vol_l, float vol_r)
{
	int16_t *inp;
	int16_t *outp;
	int cnt = len / sizeof(int16_t) / 2;
	
	inp = (int16_t*)inbuf;
	outp = (int16_t*)outbuf;
	while (cnt-- > 0) {
		*outp++ = *inp++ * vol_l;
		*outp++ = *inp++ * vol_r;
	}
	return (char*)outp - outbuf;
}

#define BUFSIZE 4096

int main(int argc, char** argv)
{
	FILE *fin;
	FILE *fout;
	char inbuf[BUFSIZE], outbuf[BUFSIZE];
	int read_len, write_len;
	char *infile = argv[1];
	char *outfile = argv[4];
	float vol_l, vol_r;

	if (argc != 5) {
		fprintf(stderr, "usage: %s infile vol_l vol_r outfile\nSpecify vol_l, vol_r in float\n", argv[0]);
		exit(1);
	}
	vol_l = strtof(argv[2], NULL);
	vol_r = strtof(argv[3], NULL);
	if ((fin = fopen(infile, "r")) == NULL) {
		perror(infile);
		exit(1);
	}
	if ((fout = fopen(outfile, "w")) == NULL) {
		perror(outfile);
		exit(1);
	}
	while (!feof(fin)) {
		read_len = fread(inbuf, 1, sizeof inbuf, fin);
		write_len = changeVol(inbuf, outbuf, read_len, vol_l, vol_r);
		fwrite(outbuf, 1, write_len, fout);
	}
	fclose(fin);
	fclose(fout);
}